The present invention relates to processes for the preparation of 3-(1-piperazinyl)-1,2-benzisothiazole or one of its pharmaceutically acceptable salts and to novel intermediates used in said processes. 3-(1-Piperazinyl)-1,2-benzisothiazole is a key intermediate useful for the preparation of 5-(2-(4-(1,2-benzisothiazol-3-yl)-1-piperazinyl)ethyl)-6-chloro-1,3-dihydr o-2H-indol-2-one (ziprasidone). This compound has neuroleptic activity.
U.S. Pat. No. 4,831,031, issued May 16, 1989, which is hereby incorporated by reference in its entirety, discloses 5-(2-(4-(1,2-benzisothiazol-3-yl)-piperazinyl)ethyl)-6-chloro-1,3-dihydro- 2H-indol-2-one hydrochloride, which has the formula ##STR1## wherein Ar is benzisothiazol-3-yl, in the hemihydrate form (hereafter "the hemihydrate").
U.S. Pat. No. 5,312,925 issued May 17, 1994, which is hereby incorporated by reference in its entirety, refers to the monohydrates hydrochloride salt of ziprasidone, processes for its preparation, and pharmaceutical compositions and methods of treating psychotic disorders.
U.S. Pat. No. 5,359,068, issued Oct. 25, 1994, which is hereby incorporated by reference in its entirety, refers to processes and intermediates for the preparation of ziprasidone.
U.S. Pat. No. 5,206,366, issued Apr. 27, 1993, which is hereby incorporated by reference in its entirety, refers to an aqueous based process for preparing ziprasidone.
U.S. Pat. No. 4,590,196, issued May 20, 1986, refers to 1-(1,2-benzisothiazol-3-yl)piperazine, which is the penultimate intermediate made by the processes of the present invention.
Japanese Patent Publication 6,220,030 published Aug. 9, 1994 refers to the preparation of 3-amino-1,2-benzisothiazole derivatives from the reaction of bis(2-cyanophenyl)disulphide derivatives with metal amides followed by treatment with an oxidizing agent.